Two-dimensional (2D)/2D Interface Engineering of a MoS₂/C₃N₄ Heterostructure for Promoted Electrocatalytic Nitrogen...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical nitrogen reduction reaction (NRR) offers sustainable ammonia production but requires efficient catalysts to boost kinetics and suppress hydrogen evolution reaction (HER).
• Two-dimensional (2D)/2D interface engineering, utilizing face-to-face contact of 2D materials, facilitates strong interfacial electronic interactions for designing advanced catalysts.

Purpose of the Study:

• To explore a 2D/2D MoS₂/C₃N₄ heterostructure as a highly active and stable catalyst for the electrochemical nitrogen reduction reaction (NRR).

Main Methods:

• Fabrication of a 2D/2D MoS₂/C₃N₄ heterostructure.
• Electrochemical characterization of the catalyst's NRR performance, including ammonia yield and Faradaic efficiency (FE).
• Density functional theory (DFT) calculations to elucidate reaction mechanisms and interfacial electronic effects.

Main Results:

• The MoS₂/C₃N₄ heterostructure achieved an NH₃ yield of 18.5 μg h^-1 mg^-1 and a FE of 17.8% at -0.3 V, significantly exceeding individual MoS₂ and C₃N₄.
• DFT calculations confirmed enhanced NRR activity due to interfacial charge transfer from C₃N₄ to MoS₂, stabilizing the *N₂H intermediate and lowering the energy barrier.
• The catalyst demonstrated preferential *H adsorption on S edge sites, suppressing competing HER and maintaining NRR selectivity.

Conclusions:

• The 2D/2D MoS₂/C₃N₄ heterostructure is a promising catalyst for efficient and selective electrochemical ammonia synthesis.
• Interfacial engineering is a viable strategy for developing advanced catalysts by leveraging electronic interactions between 2D materials.
• The catalyst's design effectively promotes NRR while mitigating the HER, leading to high ammonia production efficiency.